chest x-ray review. why order a cxr? symptoms: bad or persistent cough chest pain chest injury...
TRANSCRIPT
Why order a CXR?
SYMPTOMS: Bad or persistent
cough Chest pain Chest injury Coughing up blood Fever Shortness of breath S/P fall
Why order a CXR?
Pleural effusion Pneumothorax Hemothorax Pulmonary
embolus Trauma Monitoring chest
drainage TB
Lung cancer Chest pain
(MI?) Hypertension Screening Pneumonia COPD Asthma
Normal Chest X-Ray
Compare symmetry Review organs
(bones, lungs, heart) in sequence
Left to Right then… Top to Bottom
Random free search
Recognition of abnormal first requires knowledge
of normal. Over diagnosis of normal
variation may be more serious than omission & may lead to needless &
harmful therapy.
Chest X-Ray
Findings
Is heart enlarged or normal? Signs of heart failure and fluid overload? Does patient have pneumonia or
collapsed lung? Is there evidence of emphysema? Are there findings of an aortic
aneurysm? Is there fluid in the sac that surrounds
the lung? Is there free air under the diaphragm? Is there a tumor in the lung that could
represent cancer?
The Normal Chest X-Ray Systematically evaluate
chest wall, mediastinum, lungs, pleural space, heart, large arteries, ribs & diaphragm.
Also evaluate neck, axilla, thyroid gland & abdomen
What does air under diaphragm signify?
What is best position for this diagnosis?
The Normal Chest X-Ray
You can recognize air, water & bone density on chest x-ray
Lung fields appear dark because of air. 99% of the lung is air.
The Normal Chest X-Ray
The pulmonary vasculature, interstitial space, constitutes 1% of the lung
Gives a lacy lung pattern. Most disease states replace
air with a pathological process which usually is a liquid density and appears white.
Poor Quality CXR
Supine position Decreases lung volume, increased heart size Basilar infiltrates & interstitial spaces accentuated Increases venous return to the heart
Semi-upright position Enlarges normal structures Changes air-fluid levels
Failure to hold breath Lung structures & diaphragm blurred
Expiration film Basilar infiltrates & interstitial spaces accentuated Increased heart size
Missed Diagnoses
What is wrong with this lung tissue???
Nothing!!
But the clavicle is fractured!
10% of all x-ray interpretations have errors
Especially if there are multiple problems, don’t
focus on the most obvious abnormality!
Systematic CXR Interpretation
IDENTIFICATION Correct patient Correct date &
time Correct
examination Right vs. Left
side Comparison film
TECHNIQUE Complete exam?
All views Entire anatomical
area included? Projection
Is the film AP or PA?
The width of heart & mediastinum larger on AP film
Position
Systematic CXR Interpretation
TECHNIQUE, cont. Penetration
Over-penetrated dark films can obscure subtle pathologies
Under-penetrated white films may given impression of diffuse increased density
TECHNIQUE, cont. Inspiration
Normal, erect, inspiratory CXR shows 9.5-10.5 ribs.
Less inspiration appears diffusely denser
Diaphragms elevated causing heart & mediastinum to appear enlarged
Systematic CXR Interpretation
Order of exam is important. Start with "less significant" Tendency to stop looking as soon as find
pathology Identify atelectasis behind heart shadow! Don’t notice tip of ET tube is in right main
stem bronchus, causing the atelectasis!
Systematic CXR Interpretation
TECHNIQUE, cont. Rotation
Determined by distance between spinous process & medial clavicle
Affects heart size & shape, aortic tortuosity, mediastinal widening, density of lung fields
Systematic CXR Interpretation
INTERPRETATION Extraneous material
Contrast Lines, tubes, clips All properly located?
Soft tissues Asymmetry Calcifications
Diaphragms & Below Free air Dilated bowel Abnormal position
INTERPRETATION Bones
Fracture, dislocation
Mineralization Lung fields
Asymmetry Consolidation Nodules, lesions
Heart Size & shape Cardiothoracic ratio
Systematic CXR Interpretation
INTERPRETATION Mediastinum
Width Masses Contour
Hila Asymmetry Vessel aneurysm Trachea & carina
INTERPRETATION Pulmonary vascularity
Taper at periphery Narrow toward
upper lobes with erect film
Asymmetry Interstitial
markings Very fine If indistinct,
prominent suspect edema, fibrosis
Congestive Heart Failure
Increased heart size: cardiothoracic ratio >0.5
Large hila with indistinct markings
Fluid in interlobar fissures
Pleural effusions, alveolar edema
SARCOIDOSIS Granulomatous
Inflammation Bilateral &
symmetrical hilar & mediastinal LAD
Generalized fibrosis
ATELECTASIS No ventilation to lobe
beyond the obstruction
Trapped air absorbed by pulmonary circulation
Segmental/lobar density
Compensatory hyper-inflation of normal lungs.